I. Field of the Invention
This invention relates generally to conveyor apparatus for transporting bulk materials and more particularly to a conveyor belt cleaner or scraper mechanism that is adapted to be deployed proximate the discharge end of the conveyor for cleaning away material adhering to the conveyor belt.
II. Discussion of the Prior Art
In many industries where granular material in bulk form must be transported from one point to another, it is common practice to utilize an endless flexible elastomeric belt that is entrained about a plurality of rollers where at least one of the rollers is motor driven to thereby carry the belt in an orbital path about a frame structure in which the rollers are journaled. The products deposited on the belt are carried by it to a discharge location where the material is allowed to fall from the belt as the belt traverses the conveyor's nose roller.
It can be appreciated that with some materials there may be a tendency for them to adhere to the belt and be carried beyond the desired discharge. This causes material to be deposited underneath the conveyor and causes expensive cleanup and unnecessary wear and tear on conveyor rollers and other components. In dealing with this problem, one solution has been to provide an elongated scraper blade usually made of rubber or urethane. Other materials such as metals are also used to scrape material from the conveyor belt surface. When using an elastomer scraper or blade, the blade is typically attached to a steel bracket or tube that extends transversely across the width dimension of the endless belt proximate the nose roller of the conveyor. The blade is allowed to rub against the moving conveyor belt with a predetermined force to thereby remove the majority of the bulk product that would adhere to the conveyor belt. Because of the frictional engagement, the scraper blade is subject to wear and may require frequent spatial adjustment and ultimately replacement. Sometimes two or more scrapers will be used one after another to do a more efficient job of cleaning the belt. Keeping conveyor belt cleaners maintained can be costly for a plant or mine operator not only because of the maintenance time involved but because some of the conveyor belt cleaner replacement blades are quite expensive.
In the past, various ways have been devised for mounting conveyor belt cleaners or scrapers to the frame of a conveyor at a location proximate the nose roller thereof.
Several manufacturers such as Martin Engineering, Asgco, Argonics, and Flexco provide belt cleaners that consist of a mainframe of either square or round tubing. A flange is typically welded to the tubing and pins are used to attach the belt cleaner to the flange. One of the described cleaners is manufactured by Martin Engineering and assigned U.S. Pat. No. 4,917,231. Typically the cleaning blades used in the most popular cleaners such as those previously mentioned consist of an aluminum extrusion molded into the polymer blade. The aluminum extrusion corresponds to the upstanding flange and provides support to securely attach the polymer blade. It takes several steps to manufacture a polymer blade with an internal aluminum extrusion including cutting, preparing surfaces and bonding agents. It is a time consuming method. Blades that wear out are typically thrown away and disposing of a blade consisting of polymer and metal combined is more expensive as they are not readily recycled or re-used.
Several manufacturers provide belt cleaners that have cleaning blades that have no internal metal which attach to the mainframe by means of using internally molded “pockets” which slide over upstanding weldments on the mainframe. One of these cleaners is manufactured by Martin Engineering under U.S. Pat. No. 4,598,823. These belt cleaning systems facilitate easy maintenance but have the disadvantage of not being able to utilize a large percentage of the wear media as a large portion of the blade is used to mount it to the weldments. Sometimes a larger portion of material is thrown away than is used to clean the belt, costing money. Another disadvantage of mounting a blade onto upstanding weldments is that the weldments are prone to damage from contact with the belt on the head pulley, or sometimes the cleaner gets pulled through by the belt because of a bad splice or other defect and the weldments are bent. Manufacturing a belt cleaning system consisting of a mainframe with weldments also costs more in materials and labor. As material handling operations around the world continually try to reduce maintenance and operational costs associated with conveyor belt cleaners, there is a need for a belt cleaner assembly that is simple to maintain, cheaper to manufacture, utilizes more of the cleaner blade and is less expensive to dispose of and recycle.